The anticipation for the "Britney/Brittany" episode of "Glee" is killing us -- but now we've got your first extended video look at one of the show's dance numbers!
The video, just posted on her official website, shows Heather Morris' "Brittany" and Naya Rivera's "Santana" performing "Me Against the Music." John Stamos pops up as well.
The episode airs Tuesday.
